The pan-European FTSEurofirst 300 Index provisionally closed flat at 1,320.58 points as the ongoing crisis in Ukraine --which has dogged bourses on the continent for the past week -- continued to weigh on investor sentiment.

In Ukraine, ousted leader Viktor Yanukovich insisted Tuesday he remained the country's legitimate president and commander-in-chief, saying he would return to Kiev and appeal to the armed forces to defy any "criminal orders" handed down by his foes.

He made his remarks after Ukraine's acting president told parliament of plans to raise a new national guard to protect against internal and external threats.

On the data front, both German exports and imports surged in January, according to figures from the Federal Statistics Office. The seasonally-adjusted trade surplus narrowed to 17.2 billion euros ($32.8 billion), from 18.3 billion euros in December.

The DAX closed higher by around 0.3 percent on Tuesday, having fallen 2.9 percent in the previous two sessions.

Elsewhere, Italy's largest bank by assets, UniCredit, posted a 14 billion-euro ($19 billion) loss for 2013 after huge writedowns on acquisitions and bad loans, as it attempted to clean up its balance sheet ahead of a sector-wide health check by European regulators.

However, shares in the bank provisionally closed up by 6.2 percent as the bank said it did not need to raise capital and investors responded positively to efforts to tidy up its balance sheet.

In Italy there was more positive data on Tuesday, after fourth-quarter gross domestic product (GDP) grew 0.1 percent from the third, in line with expectations by analysts in a Reuters poll. This followed yesterday's numbers, which showed Italian industrial output — on a seasonally adjusted basis — had risen 1 percent in January, beating estimates of a 0.4 percent rise.

Portugal's growth figures beat estimates, with GDP growth of 0.6 percent in the last quarter. Portuguese stocks posted solid gains after the news with the PSI 20 Index higher by 0.7 percent.

Meanwhile on Tuesday, the European Central Bank detailed the next phase of its asset quality review. It said that 3.72 trillion euros ($5.2 trillion) of risk-weighted assets would be examined, and an average of 1,250 loans per bank would be reviewed by August, with even more slated for Europe's biggest banks.

In the U.K., Bank of England Governor Mark Carney and colleague Paul Fisher received a grilling from lawmakers as part of the investigation into alleged manipulation of the currency markets. Carney and Fisher were quizzed about allegations that officials "condoned or were informed of manipulation in the foreign exchange market or the sharing of confidential client information."